The present invention relates to a transition based feedforward equalization method and apparatus implemented with lookup table circuits to equalize pulse amplitude modulation (“PAM”) signals. Communication systems are generally composed of a transmitter, a receiver, and a channel. The transmitter generates a signal conveying information, which, after being transmitted over a channel, is received and recovered at the receiver. For optical based communications such as communications using vertical cavity surface emitting lasers (VCSELs), electro-absorption modulated lasers (EMLs), or directly modulated lasers (DMLs), the lasers are non-linear laser sources. In addition, the channel and the receiver may induce distortions on the signal due to linear and/or non-linear phenomena. The present invention presents a method and apparatus to implement a feedforward equalization to compensate for these impairments in linear and/or non-linear drivers and channels.